1. Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Argentina.
2. Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
3. Osservatorio Astronomico di Padova, Sede di Asiago, Italia
4. National Astronomical Observatory Rozhen, Smolyan, Bulgaria
5. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, Argentina
6. Instituto de Astronomía,Universidad Nacional Autónoma de Mexico, Mexico
7. Space Telescope Science Institute, Baltimore, U.S.A.

Electronic mail: oferrer@fcaglp.unlp.edu.ar

The symbiotic binary MWC560 is a very peculiar system. Consisting of a M giant and a magnetic white dwarf companion, its behaviour resembles only that of CH Cyg. The massive and fast outflows and jets, the rapid variations in brightness with a time scale of the order of twenty minutes, and the alternance between low and high activity phases, are phenomena which only could be caused by the presence of the magnetic white dwarf secondary (Mikolajewski et al. 1997).

The spectrum is clearly dominated by narrow emission lines of singly ionized metals and by the Balmer lines, which show variable profiles, consisting of a strong emission component and complex absorption profiles displaying two kinds of components: a broad component with velocities of the order of - 300 km s^-1, always present, and violet shifted components, with velocities between -300 km s^-1and -7000 km s^-1, produced by the discrete ejection of material along the line of sight (Tomov et al. 1990, 1992).

The radial velocities of the narrow emission lines do not show any change, and so do the velocities of the absorption lines of the M giant, supporting then the idea of face-on location for the orbital plane of the system (Tomov & Kolev 1997). The emission of the Balmer lines could be formed in an accretion disk and/or envelope around the hot companion, and the violet-shifted absorption components would be caused by the bipolar ejection of highly collimated jets by the magnetized white dwarf (Tomov & Kolev 1997). Probable spectral signatures of this bipolar ejection were previously presented (Tomov et al 1997).

We are presenting here a clear evidence of the presence of the corresponding red-shifted jets, signatures of which are seen in the behaviour of the red wing of the H emission profiles, mirroring the strongly violet-shifted absorption components when present. We obtained high resolution H profiles secured between 1993 and 1998 with the Rozhen (Bulgaria) 2-m, the Asiago (Italy) 1.82-m, the San Pedro Martir (Mexico) 2.1-m, and the CASLEO (Argentina) 2.15-m telescopes.

Only two of them are shown here: In the Figure 1, (16sept96), only the broad absorption is seen, while in the Figure 2, (10mar98), a violet-shifted absorption is clearly mirrored by the corresponding emission component.

Fig.1:

Fig.2:

References:

Mikolajewski M., Tomov T., Mikolajewska J.:1997, in Mikolajewska J. (ed.) Physical Processes in Symbiotic Binaries, p.93

Tomov T., Kolev D., Georgiev L., et al., 1990, Nat 346,637

Tomov T., Zamanov R., Kolev D., et al.: 1992, MNRAS, 258,23

Tomov T., Kolev D.,: 1997, Astron. Astropys. Suppl. Ser. 122, 43

Tomov T., Kolev D., Munari U.: 1997, in Mikolajewska J. (ed.) Physical Processes in Symbiotic Binaries, p. 197